A person who is irresolute or fearful.
A cnidarian, a member of the phylum Cnidaria.
A scyphozoan, a member of the class Scyphozoa (the true jellies).
A ctenophore, a member of the phylum Ctenophora (the comb jellies).
A sudoku technique involving possible cell locations for a digit, or pair, or triple, in uniquely four rows and four columns only. This allows for the elimination of candidates around the grid.